Genetic mutation that makes us once bitten, twice shy identified

December 7th, 2007 - 1:51 pm ICT by admin  

London, Dec 7 (ANI): Most people tend to learn from their mistakes and avoid a similar fate in the future. Now, researchers have found that the reason we are able to do so, is because of a gene that makes us once bitten, twice shy.

The researchers behind the finding are Tilmann Klein and Markus Ullsperger at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany.

They discovered that a single mutation in a gene is what determines whether people repeat their mistakes.

The mutation, the researchers say, leaves people with lesser D2 receptors in the brain that are activated when levels of the neurotransmitter dopamine drop. Dopamine is not only responsible for signalling fun and pleasure in the brain, but the neurotransmitter also helps in learning.

Klein and Ullsperger theorised that since dopamine is a chemical treat that urges the brain to repeat a choice if it is pleasurable, if not, then D2 receptors should be activated so that people dont make the same mistake.

The researchers then tested this on a group of 26 men, twelve of whom had the gene mutation for low numbers of D2 receptors.

As a part of the study the subjects were shown sets of two symbols on a computer screen, and were asked to select one. The choice was followed by either a smiley face or a frown flashing on the screen.

The researchers then tested to check whether the men had learnt to choose the symbol that was the most positively reinforced and avoid the one that was the most negatively reinforced.

According to Science 1, they found that men with fewer D2 receptors had trouble avoiding their mistakes, reports Nature.

Brain imaging then used confirmed that the region called the rostral cingulate zone was involved in learning from mistakes. This particular region was found to be more active in the volunteers with normal D2 levels during the learning sessions, compared to those with the D2 mutation.

A brain region key to forming memories, the hippocampus, was also more active in the volunteers with normal D2 levels. (ANI)

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